1) Don't keep your battery in if this is a desktop replacement. Only have the battery in when you are going to be portable.
2) Yes More Power Options then under Additional plans is High performance.
3) Click the options to the left to configure your specific needs. For example I use hibernation then shut down when I hit the power button, or set the lid shut to do nothing.
4) Click your wireless then select the network and sharing Center. Change Adapters settings on the left. Double click the wireless connection. Click Properties at the bottom then power Management tab. Change as you feel appropriate.